Hydraulic pump and motor



M. K. INGOLDBY.

HYDRAULIC PUMP AND MOTOR.

APPLICATION, FILED NOV. 28, 1921.

Patented Aug. 8, 1922.

v2 SHEETSSHEET I.

K. INGOLDBY. HYDRAULIC PUMP AND MOTOR.

APPLICATION FILED NOV- 28, I921.

Patented Aug. 8, 1922.

2 SHEETS-SHEET 2.

UNHTED STATES MAURICE KERR INGOLDBY, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNOR TO THE earner crates.

VARIABIJE SPEED GEAR, LIMITED, OF WESTMINSTER, LONDON, ENGLAND.

menses.

nrnnn'onrc rune AND moron.

Patented Aug. 8, 31922.

Application filed November 28, 1921. Serial No. 518,186.

To all whom it may concern Be it known that I, MAURICE KERR IN- GOLDBY, a subject of the King of Great Britain, of Broadway Court, Broadway, Westminster, in the county of London, England,

'This inventlon relates to variable stroke hydraulic pumps and motors ofthe kind having a tiltable or other movable strokecontrolling member whose adjustment varies the stroke of the pistons of the pump or motor. r f

In such pumps or motors it has been found that the resultant pressure on the said stroke-controlling member set up during Working ofiers'considerable resistance to the adjustment of this member to increase the stroke in the case of a pump and to reduce the stroke in the case of a motor, such resistance preventing the easy manipulation of the control hand-lever, hand-wheel'or other device when the stroke-controlling member is adjusted thereby.

According to the invention a device is provided for balancing or approximately balancing the aforesaid resistance ofl'ered to the adjustment of the stroke-controlling member, this device preferably comprising a piston or ram which operates upon a part connected to the said member and works n a cylinder placed in communication with the pressure fluid in the pump or motor system; in this manner, since the resistance to the adjustment of the stroke-controlling member is dependent upon the pressure in the system, it can be ensured that the said member is at all positions in a state of balance so that it can be easily adjusted by hand as aforesaid. In cases where the stroke-controlling member is intended to be ing or eliminating the, vibratory movements of the stroke-controlling member that occur during the working'of the pump or motor even when this member is balanced as aforesaid. The cylinderof the said dash-potdevice preferably contains fluid under pres- Sure which, while allowing the piston to remain statically balanced, serves to more ef- Figure 2 is a sectional side elevation shewing the balancing device of Figure 1 used in conjunction with a stroke-controlling member which is operated through the intermediary of irreversible or self-locking gearv Figure 3 is a sectional side elevation of a constructional form of the aforesaid dashpot device used in conjunction with the balancing device of Figure 1.

Fig. 4 is a vertical section showing the improvement employed with a pump of the well known Williams-Janney type.

In the examples shewn A represents the tilting box which controls the stroke of the pistons of a pump or motorof the kind having a number of cylinders arranged in a r0- tating cylinder barrel parallel to the axis of rotation. This tilting box is angularly dis-.

placeable about the pivot a" and has connected thereto an arm A which, in Figures 1 and 3, is operated directly by a rod a leading to the control lever and which, in Figure 2, is in the form of a worm-wheel sector meshing with a worm m operated through a pinion a? and a rack A by a rod a connected to the said rack.

Referring to Figure 1, B is the doubleacting piston of the balancing device and B is the cylinder in which this piston works, the ends of this cylinder communicating with pipes 71', b one leading to the pressure system and the other to'the suction system.

thereon will at all positions of the tilting box operate to balance or approximately balance the resistance of the said tilting box to movement in the stroke-increasing direction in the case of a stroke-decreasing direction in the case of a motor.

In Figure 2 the arrangement of the balancing piston and cylinder is similar to that of Figure 1 except that the piston rod 5. is connected directl to the tilting box A.

In Figure 3, (J represents the piston and C the cylinder of the aforesaid dash-pot device which is shewn as being used in conjunction with the arrangement of balancing device shown by Figure 1 but which can be used without the latter device. The dash-pot. device is made double-acting and the degree of its retarding action can be controlled by an adjustable plug C as is well understood. In the construction shown the piston C is arranged in line with the piston of the balancing'device and the respective piston rods 0, b are connected at the same point to the arm A of the tilting box. The fluid .in the cylinder C may asaforesaid he placed under pressure preferably by connecting either or both ends of the cylinder by a pipe or pipes to a source of fluid pressure which may give a constant pressure or pressures varying in accordance with the pressure of the fluid within the pump or motor,-the pipes inthe latter case being connected to a suitable portion of the ressure system of the pump or motor; in igure 4 (f, (J are pipes leading from a pipe c to the ends of the cylinder C. This pipe communicates with a casing containing a throwover valve C and the ends of this casing communicate by pipes 0, 0 with the pressure and suction systems of the ump: 'Ihis valve ensures that the cylinder (1 shall communicate with the pressure system when the direction of flow of the liquid pumped by the pump is reversed.

It will be understood that the aforesaid dash-pot device will not be required in the construction shewn by Figure 2 and in other constructions involving the use of irreversi ble or self-locking gearing as such gearing prevents any vibratory movements of the tilting box or its equivalent from being transmitted to the control lever.

Althou h the invention has been described in its app ication to a pump or motor having parallel cylinders and a tilting box, it is to be understood that it may also be used in conjunction with other types of variable stroke pumps or motors, for example one in which the cylinders are radial and the stroke pump and in the r ment of said member in 1. In a variable stroke fluid pump having I at least one cylinder and piston,-a member controlling the stroke of the piston, and balancing means acting on said member interposed between the same and a part which remains stationary during the stroke controlling adjustments of said membenjor approximately balancing the resistance offered by the fluid to the adjustment of said member in the stroke increasin direction.

2. In a variable stroke uid motor having at least one cylinder and piston, a member controlling the stroke'of the piston, and balancing means acting on said member interposed betvreen the same and a part which remains stationary during the stroke controlling adjustments of said member, for approximately balancing the resistance offered by the fluid to the adjustment of said member-in the stroke decreasing direction.

3. In a variable stroke fluid pump having at least'one' cylinder and piston, a member controlling the stroke ofthe piston, and a fluid operated balancing device having connections with the pump whereby'said device is under the control of the pressure of the fluid in the pump, the balancing'device being interposed between said memberand a part which remains stationary during the stroke controlling" adjustments of said member, for approximately balancin offered by the fluid to the ad ustment of said member in the stroke increasing direction.

4. In a variable strokefluid motor having at least one cylinder and iston, a member controlling the stroke of t lue'piston, and a fluid operating balancing device having connections with the motor whereby said device is under the control of the pressure of the fluid in the motor, the balancing device being interposed between said member and a part which remains stationary during the stroke controlling adjustments of said-member, for approximately balancing the .re-

sistance'ofl'ered by the fluid to the adjustthe stroke decreas' ing direction.

the resistance 5. In a variable stroke fluid pump, the:

combination with the member controlling the stroke, of a cylinder, av piston working in said cylinder, means for placing said cylinv der in communication with the pressure system of the pump and means for connecting said piston to the stroke controlling member said piston to the stroke controlling member for approximately balancing the resistance oflere'd by the fluid to the adjustment of said member in the stroke decreasing direction;

7. In a variable stroke and reversible fluid pump, the combination with the member controlling and reversing the stroke, of a cylinder, a double acting piston working in said cylinder, means for placing one end of said cylinder in communication with the pressure system of the pump and the other in com-- munication with the suction system of the pump and means for connecting said piston to the stroke controlling and reversing member for approximately balancing the resistance offered by the fluid to the adjustment of said member in the stroke increasing direction.

8. In a variable stroke and reversible fluid motor, the combination With the member controlling and reversing the stroke, of a cylinder, a double acting piston Working in said cylinder, means for placing one end of said cylinder in communication with the buffer devicev which is interposed between said member and a part which remains stationary during'the stroke controlling adjust ments of said member, -for damping the vibratory movements of said member that occur during the workin of the motor.

10. In a variable stro e fluid motor having at least one cylinder and piston, a member controlling the stroke of the piston, and a buffer device which is interposed between said member and a part which remains stationary during the stroke controlling adjustments of said member, for damp'ing'the. vibratory movements of said member that occur during-the working of the motor.

11. In a variable stroke fluid pump having at least one cylinder and piston, a member controlling the stroke of the piston, and a dash-pot device which is interposed between said member and a part which remains stationary during the stroke controlling adjustments of said member, for damping the vibratory movements of the said member 1 that occur during the working of the pump.

12. Ina variable stroke fluid motor having I at least one cylinder and piston, a member controlling the stroke of the piston, and a dash-pot device which is interposed between said member and a part which remains stationary during the stroke controlling adjustments of said member, for damping the vibratory movements of said member thatv occur during the working of the motor.

13. In a variable stroke fluid pump having at least one cylinder and piston, a member controlling the stroke of the piston, and a dash-pot cylinder containing fluid under pressure and carried by a part which remains stationary during stroke controlling "adjustments of said member, a piston working in said cylinder and means for connecting said piston to said member for damping the vibratory movements of said member that occur during the working of the pump.

14. In a'variable stroke fluid motor having at least one cylinder and piston, a. member controlling the stroke of the piston, and. adash-pot cylinder containing fluid under pressure and carried by a part which remains stationary during stroke controlling adjustments of said member, a piston work- .ing in said cylinder and means for connecting said piston to said member for damping the vibratory movements of said member that occur durin the working of the motor.

15. In a varia 1e stroke fluid pump having at least one cylinder and iston, a member controlling the stroke of t e piston, and a dash-pot cylinder carried by a part which remains stationary durin stroke controlling adjustments of said mem r, a piston Working in said cylinder, means for placing said 0 linder in communication with a source of mid pressure supply, and means for connecting said piston to said member for damping the vibratory movements ofsaid memberthat occur during the working, of

the pump.

16. In a variable stroke fluid motor having at least one cylinder and piston, a member controlling the stroke of the pistomandi a dash-pot cylinder carried by arpart which remains stationary during stroke controlling adjustments of said member, a piston-Workin in said cylinder, means for placing said) cy inder in communication with a source of fluid premure supply, and means for connecting said piston to said member for damping the vibratory movements of said member that occurs during the working of the motor.

17 In a variable stroke and reversible fluid pump having at least one cylinder and a source of fluid pressure supply, and means for connecting said piston to said member her, for approximately balancing the resistance offered by the fluidto theadjust- 9.0

ment of said member .in the stroke increas:

ing direction, and a device which is also interposed between said member and a part which remains stationary during the strokev for damping the vibratory movements ofcontrolling adjustments of said member, 35 said member that occur during the working for damping the vibratory movements of of the pump. said member that occur during the working 18. In a variable-stroke and reversible of the ump.

fluid motor having at least one cylinder and 20 n a variable stroke fluid motor havpiston, a member controlling and reversing ing at least one cylinder and piston, a mem- 40 the stroke of the piston, and a dash-pot cylinder carried by a part which remains stationary during stroke controlling adjustments of said member, a piston working in said cylinder, means for placing said cylinder in communication with a source of fluid pressure supply, and means for connecting said piston to said member for damping the vibratory movements of said member that occur'during the workingof the motor.

19. In a variable stroke fluid pump having at least one cylinder and piston, a memher controlling the stroke of thepiston, and

means interposed between said member and apart, which remains stationary difring the stroke controlling adjustments of said memher controlling the stroke of the'piston, and means interposed between said member and a part which remains stationary during the stroke controlling adjustments of said member, for approximately balancing the resistance ofl'ered by the fluidto the adjustment of said member in the stroke decreasing direction, and a device which is also inter-' posed between said member and a part which remains static-nary during the stroke controlling adjustments of said member, for damping the Vibratory movements of said member that occur during the working of the motor.

MAURICE KERR ,INGOLDBY. 

